Build & Play Robot Mini Golf!

Create, build, and play an obstacle course for Brush Bots! This is an activity for all ages that teaches the basics of circuits and design thinking while encouraging and inspiring creativity, discovery, and collaboration. Most importantly, it's super fun! (But seriously though, watch the video it's adorbs and will make you smile)

This tutorial will show you how to build (and source parts for) a Brush Bot, how to design and build mini golf inspired obstacles, and how to use the design thinking process to create a Brush Bot that can accomplish each of the obstacles. Go forth and build your own Robot Mini Golf course!!

Tools

• Scissors
• Hot glue gun(s) + hot glue sticks
• Wire cutters/strippers
• Masking Tape

Materials

1. Electronics

• Electric toothbrush
• AA battery (you can also use a 9V if you wanna get real crazy)
• 1 x AA battery box
• Conductive material (e.g. copper tape, wire, paperclips, aluminum foil, etc.)

2. Brush Bot Body & Feet

Since there are tons of ways to build the body, no list is absolute. Here are some suggestions (upcycling materials are highly encouraged & also cut down on cost!):

• Toothbrush bristles
• Styrofoam/plastic/paper cups
• Paper plates
• Cardboard
• Tupperware
• Toothpicks and/or wooden skewers
• Popsicle sticks
• Styrofoam pieces

3. Obstacles

• Cardboard, cardboard, and more cardboard!
• Art supplies
• And maybe throw in some electronics in there also (see Step 4) :)

Brush Bots, or Bristle Bots, are the simplest possible form of a robot: a motor with a counterweight and a battery attached to simple body. The counterweight causes the motor to shake, which, in turn, causes the body to shake.

The name "Brush Bot" comes from a common design that uses toothbrush bristles as the "feet". The term has been adapted to refer to any simple robot based on the counterweight motor design. Another super fun variation are Art Bots, which use markers or other materials to draw while they wobble around!

There are tons of ways to build a Brush Bot. A couple of approaches are shown in the photos above.

My obstacles were inspired by mini golf and through my experience in teaching Brush Bots and seeing various approaches from students and educators. I wanted obstacles that would be fun, accessible, and interesting for kids and adults, so I came up with four obstacles of varying difficulty.

Obstacle 1: Enter the Arena

Starting from 1 - 2 feet away, the Brush Bot must enter the opening to an arena. This can be made by marking an arena with tape, or by building a simple fence from cardboard.

Obstacle 2: Spiral Maze

The spiral maze is a crowd favorite and is a great obstacle for younger kids to tackle. Build the spiral maze by scoring a long piece of cardboard (~ 4 feet), then gluing it in a spiral pattern on a 2' x 2' cardboard square.

I decorated mine to look like a galaxy by spray painting the outside gold and the inside black, then gluing glow-in-the-dark stars on the inside.

Obstacle 3: Ramp

Although easy to make, this obstacle has proved to be the most challenging. I recommend using a low incline (less than 15 degrees) and adding a rough surface (e.g. sandpaper) on top of the cardboard.

Build the ramp by cutting out two identical triangles and then adhering a cardboard square on top.

Obstacle 4: Robot Head

By far the most fun, but a bit more complicated. I wrote a quick Arduino sketch to move a servo motor and added an IR breakbeam switch to trigger some LEDs when a Brush Bot goes into the mouth.

Recreate or modify this Robot Head or create your own whimsical obstacle!

1. Dismantle and gut an electric toothbrush! Your mission: find the motor.

For the Assure-brand "Soft Bristle Electric Toothbrushes" that you can get at the Dollar Store (just $1 woot woot!), twist off the bottom, pull out the battery holder, and pull out the motor. You may need to tap (or hit) the open toothbrush on the floor to get the motor out, or (gently) use pliers to pull it out.

2. Grab (or build!!) a battery box, and connect the positive side (red wire) to one of the motor leads*.

3. Connect the negative side of the battery box (black wire) to the other motor lead.

Orientation doesn't matter -- try switching them and see what happens!

4. Design and build a body for the lil 'bot and give it a way to move. Iteration through different designs is recommended and encouraged!

Some common and easy ways to make the Brush Bot move are to use toothbrush bristles, toothpicks, or popsicle sticks to make legs/feet. Try different objects and object placements to see what happens.

*The motor leads are those gold tabs with holes by the white cap of the motor.

Design Thinking is a problem-solving method. Traditionally, it's applied for design of hardware and software products in various engineering disciplines, but this process can be applied to pretty much any aspect of life. The Design Thinking process comes in variety of flavors, here is a common breakdown:

1. Design: Who is your audience? What, or who, are you designing for? What are constraints for your product/project?

2. Ideate: How can you solve this problem? Come up with at least 3 - 5 different approaches -- impossible solutions are totally acceptable in this phase.

3. Prototype: Choose one of your (possible) solutions and build it.

4. Test/Observe: Test your prototype and observe how it behaves. Does it solve your problem? If not, what's wrong with it? If it does, can it be done in a simpler or easier way?

5. Adjust: Change your prototype based on your testing and observations.

Repeat steps 3 - 5 until you've arrived at a solution that solves your problem, satisfies your audience (or teacher), and meets any design constraints.

For Educators:

You can go through the design thinking process before, during, or after the workshop. One of the benefits of having obstacles to conquer is that it motivates students to naturally go through this process without having to sit and think about it.

That's it! You're ready to tackle and challenge your students, friends, and/or family to a game of Robot Mini Golf!

A bonus feature would be to add prizes for anyone who successfully completes either one or all of the obstacles. My favorite method is to give out small prizes (e.g. stickers or buttons) to anyone who builds a Brush Bot that completes at least one of the obstacles, and a larger prize for anyone whose Brush Bot successfully completes all of the obstacles. This is a great way to adapt this into a workshop for folks of all ages -- older kids and adults can try to conquer all of the obstacles while the younger kids still get to participate and have a blast! :D

Please feel free to share your Robot Mini Golf stories in the comments! Would lovelovelove to hear anecdotes of how this activity went with students and/or to see photos of your unique Brush Bot(s) and obstacle course creations!